Description
void echo ( string $arg1 [, string $... ] )

Outputs all parameters.

echo() is not actually a function (it is a language construct), so you are not required to use parentheses with it. echo() (unlike some other language constructs) does not behave like a function, so it cannot always be used in the context of a function. Additionally, if you want to pass more than one parameter to echo(), the parameters must not be enclosed within parentheses.

echo() also has a shortcut syntax, where you can immediately follow the opening tag with an equals sign. This short syntax only works with the short_open_tag configuration setting enabled.
I have <?=$foo?> foo.

Parameters
arg1:    The parameter to output.
... 

Return Values
No value is returned. 